Answering the question:

A 1.0kg box slides without friction around the loop-de-loop apparatus as shown in the diagram. If the object starts from rest at point A, and the radius of the loop is 0.75m, what is the speed of the box at point B?

 

The model that I created is a scaled down version of the loop de loop question 13  in Lesson 4 in the Energy Unit. Point A and B are labeled along with their actual height and their intended heights from the problem. I have also labelled the intended radius and the loops actual radius. In the book this question takes place in a frictionless world. Obviously the variable of friction would certainly exist in any real world environment therefore this is something we must take into account.

 

 

My steps:

Step 1: Originally I had hoped to replicate the question exactly. This proved to be difficult and in the end unattainable due to the conditions and limitations of the 3D printing process. I started by making the loop. I did this by using a corkscrew and shortening it. I then copied the corkscrew and made it a hole, putting it in the original corkscrew, fusing them together which created the track that the ball (or marble) would be able to travel through.

I then made the ramp that would help the ball accelerate and go around the loop de loop. I also made the off ramp. I did this by following a similar strategy as the loop but this time I started with a cylinder instead of a corkscrew.

As I investigated further I found a few issues with my original design. To start the ramp was not steep enough and the angle that the down ramp meet the loop made it unlikely the marble would actually be able to circle the loop. The second problem came with the logistics of how the loop would print. It would be futile to continue to try to 3D print the loop and so I decided to change up the design. The final issue with my original design was that the rectangle holding up the ramp needed more support so that it could print.

Step 2: For my second design I removed the loop as mentioned above. I decided that I would attempt to create a loop using different material once the down ramp and the off ramp where printed. After removing the loop I added a support underneath the down ramp using a 3D triangle. This designed seemed much more realistic. The only issue this time was that I needed to fuse the different pieces together and lay them on their sides so that they would be able to print.

 

Step 3: I fused the ramps each individual ramp together and rotated them using the angles tool. They where now ready to print. After they printed all that was left to be done was making the loop de loop to size. I waited for the ramps to print to make the loop de loop so I could be certain the loop de loop I made would work and the marble would have a chance at getting around the loop de loop.

 

 

 

 

 

 

 

 

 

 

 

 

Step 4: The next step was making the loop and putting it all together. This proved more challenging then I had predicted but in the end I am proud of what I was able to put together and I think it looks aesthetically pleasing and accurately portrays the essence of the question. For my first attempt at making the loop I used modelling foam. This substance is similar to modelling clay but slightly less messy and easier to use. Unfortunately I did not like the outcome and found it to be a little messy and didn’t give off the polished look that I was hoping for, not only that but it definitely didn’t give off the illusion that the marble would be able to make it’s way all the way around the loop. The final issue with the modeling clay was that it would not stand up on it’s own and needed supports. Even with the support’s it was not stable and so I decided to try something else.

 

 

 

 

 

 

 

 

 

I decided to use bendable pipe which turned out to be easier then I had predicted. First I had to cut a little chunk off the bottom of the 3D printed down ramp because otherwise the pipe would not create a fluid line for the marble to travel through. I reutilized this piece later. I cut the pipe to a size that I thought was fitting and then superglued the down ramp to the pipe. I left this overnight to dry and stabilize. The next day I used a hair dryer to make the pipe more bendable and turned it into the loop formation. I then superglued it to the off ramp I used the piece I had cut off to help create a more smooth transition from the loop to the off ramp. The final step was labelling everything! In addition I was also unable to find a marble small enough to hypothetically go down the ramp so I made a small ball out of modelling foam. Unfortunately this modelling foam ball was too light to show up on any scale I used so I was not able to label the weight of the ball.

 

Even though this project presented me with many challenges I think the end product helps enhance the question and I think the model is a very good example of what the question was trying to communicate.